Indeed, it goes back to early days of the brewing business, when beer was first dispensed in bottles. 'The expression church key is old in the brewing business,' he wrote. 'I worked in a brewery for about 35 years and everybody carried a bottle opener or church key, perhaps so called because it looked like the top end of the kind of heavy ornate key used to unlock church doors.

and if you do a "church key image" search, you'll see what the originals looked like and the resemblance to actual church keys.

When I was young my Dad always carried "eine Kirche Schlussel" or a church key. One of my first jobs as a kid/apprentice was carrying the beer to Dad's crew, this was back in the late 50's. I always had to have a spare church key with me -- just in case one was dropped. My Dad used to tell me that it was called a church key because it resembled the church keys/skeleton style keys that they used to use to open beer bottles. Brewing beer in Germany goes back literally hundreds of years - many centuries before the Regenheitsgebot or the Bavarian Purity Law of 1513. Oh yeah, I still have some of the church keys that our local brewery used to distribute free with a 24 of beer

Prior to Google, I attempted to use the patent office data base search engine which returned a multi page image report which was not visible on my phone or laptop browser. Possibly a temporary technical difficulty.

Not the first time I have experienced difficulty researching the patent office website.

I have always had trouble finding things on the patent office site. I found I was usually out of luck unless I had a patent number to start with. Their classification numbers never helped me much. Now that Google has the patent search, it is a lot easier to find something (once you figure out how to find their patent search!). I usually just go to USPTO if I have a patent number and need an image for publication.